alpha-methyl benzyl esters of campholic and fencholic acids



Patented July 17, 1951 r AND FENCHOLIC ACIDS William A. Fry, Midland, Mich, assi'ghor to' The Dow Chemical Compan poration of Delaware y, Midland, Mich; a @or- Q No Drawing. Application May 20, 1949', j Serial No. 94 ,520 I This invention relates to new isomeric amethyl benzyl esters of campholic acid (I) and fencholic acid (II) having the respective formulas The invention also relates to new compositions of matter comprising said isomeric esters as stabilizing plasticizers in polymeric vinylidene chloride products.

The polymer of vinylidene chloride and many 20 3 Claims. (01. 260468) not and is assumed to be an evidence of partial decomposition. Because of the many desirable properties of polymeric vinylidene chloride products, a means is sought to overcome or prevent the tendency for such products to decompose on heating. In common with other thermoplastics,

it is necessary to plasticize polymeric vinylidene chloride products to reduce their viscosity at molding or extrusion temperatures, even though the plasticizer may not all be retained in the shaped article. any, heat stabilizing effect on polymeric vinylidene chloride products.

It is, accordingly, among the objects of the present invention to provide a composition of Most plasticizers have little, if

matter comprising a polymeric vinylidene chloride product stabilized against the decompositional effects of heat. A related object is to provide a heat stabilizer in the form of a plasticizer for polymeric vinylidene chloride products. An-

other object is to provide certain new esters exhibiting the desired properties.

I have prepared a-methyl benzyl campholate and a-methyl benzyl fencholate and have now found that the stated objects may be attained through the incorporation in polymeric vinylidene chloride products of fromabout 1 to about 10 per cent by weight, ofeither of these isomeric esters. If the ester is bein relied on both as a plasticizer and a stabilizer, it will usually be employed in amounts of 6 to 10 percent. If, however, other plasticizers are used, and a stabilizing eifect only is desired, amounts of l to 6 per cent of the new esters will be sufiicienth The isomeric estersnamed' above were prepared by converting fencholic or cainpholic acid into the corresponding acid chloride with thionyl chloride. A mole of the acid chloride was added slowly to a solution of one mole of pyridine in ethylene dichloride at a temperature of about 5C. To this mixture, a mole of a-methyl benzyl alcohol was slowly added at a temperature of about 17 to 18 0. The mixture was then heated at a temperature of about 40 C. for 2 hours. At the end of this period, the pyridine hydrochloride was extracted by washing the mixture with water. The ethylene dichloride was distilled off and the ester was purified by distillation under reduced pressure. The new esters have the following physical properties:

These compounds have been found useful in stabilizin and plasticizing polymeric vinylidene chloride products for fabrication into films, filaments, and other articles by hot extrusion or molding operations. They are especially useful by making possible the preparation of odorless thermostable plastic articles.

By way of example, a copolymer of about per cent vinylidene chloride and about 15 per cent vinyl chloride was thoroughly mixed with each of the above-named isomeric esters. A given weight of each such milled product was heated at C. and the elapsed time (in minutes) noted before a rapid evolution of hydrogen chloride gas was first observed. For convenience, this time value in minutes shall here after be referred to as the T-value. The amount of decomposition of a polymeric vinylidene chloride product may be judged from its Composition: Average T-value a-Methyl benzyl campholate plus copolymer 11 a-Methyl benzyl fencholate plus copolymer 11 Blank (unmodified copolymer) 4 The invention is not limited to v the us'eof the disclosed compounds in the particular copolymer of the example, but is applicable generally to all polymeric vinylidene chloride compositions which tend to darken and decompose when heated, prolonging in each case the useful life of th'e'polymer:

under exposure to heat. No advantage has been found in using over 10 percent ofone of the-new esters, as such amounts are'not needed for stability and are not-retainedin the fabricated articles.

I claim;

1; Thea-methyl benzyl ester of an acid selected from the: group consistingof campholicand fencholi'c acids.-

2; a-Methyl benzyl campholate, aliquid distillingrat202" C. under 38 millimeters pressure, having a specific gravity of 0.9972 at 25/25 C., a refractive index of 1.4990 at 25 C., and the formula 3. a-Methyl benzyl fencholate, a liquid distilling at 205 C. under 38 millimeters pressure, having 'a specific gravity of 0.9795 at 25/25 C., a refractive index of 1.4914 at 25? C., and the formula WILLIAM A. FRY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS CH-'- 111-112 C Number Name Date 707,278. Summers Aug. 19, 1902 2,228,256 Christiansen Jan. 14, 1941 2,273,262 Hanson et al. Feb. 17, 1942 30 2,287,189 Matheson et a1. June 23, 1942 

1. THE A-METHYL BENZYL ESTER OF AN ACID SELECTED FROM THE GROUP CONSISTING OF CAMPHOLIC AND FENCHOLIC ACIDS. 